In the field of ultrasonic diagnostics it is necessary to obtain acoustic images of body tissue. In order to produce real-time images, beams of ultrasonic energy from an ultrasonic probe are rapidly transmitted into the body tissue of a patient and echos received by the ultrasonic probe are rapidly processed in an image format suitable for display. Desirably, the probe will produce an image over a wide field of view using a sector scan format. A sector scan image is produced by repeatedly transmitting and receiving ultrasonic energy in radial directions from the probe. The ultrasonic beam is directed by a mechanically moving transducer which is physically swept about a pivot axis through an arc to produce a sector scan.
The prior art is replete with examples of ultrasonic transducer probe assemblies, such as those disclosed in U.S. Pat. No. 4,149,419 entitled "Ultrasonic Transducer Probe" issued Apr. 17, 1979 to R. Connell et al.; U.S. Pat. No. 3,955,561 entitled "Cardioscan Probe" issued May 17, 1976 to R. Eggleton; U.S. Pat. No. 4,421,118 entitled "Ultrasonic Transducer" issued Dec. 20, 1983 to J. Dow et al.; U.S. Pat. No. 4,479,388 entitled "Ultrasonic Transducer and Drive System" issued on Oct. 30, 1984 to T. Matzuk; U.S. Pat. No. 4,399,703 entitled "Ultrasonic Transducer and Integral Drive Circuit Therefor" issued on Aug. 23, 1983 to T. Matzuk; U.S. Pat. No. 4,092,867 entitled "Ultrasonic Scanning Apparatus" issued on June 6, 1978 to T. Matzuk; U.S. Pat. No. 4,246,792 entitled "Self-Contained Ultrasonic Scanner" issued Jan. 27, 1981 to T. Matzuk; and U.S. Pat. No. 4,398,425 entitled "Ultrasonic Scanning Transducer" issued on Aug. 16, 1983 to T. Matzuk. In addition, an ultrasonic transducer probe assembly is disclosed in the subject co-applicant's copending U.S. patent application Ser. No. 047,479 filed on May 11, 1987 entitled "Ultrasonic Transducer Probe Assembly".
Although all of the above-referenced patent disclosures address varying problems associated with the use of ultrasonic transducer imaging, none have addressed the particular problems associated with the use of ultrasonic transducer probe assemblies in applications such as prostate applications, where space constraints prevent manipulation of the probe to effectuate differing scan directions to allow proper identification and sizing of problematic or diseased body tissue in a patient. As such, the use of ultrasonic imaging technique in the detection of body disorders or disease associated in space intensive applications has been limited and has not fully reached its full potential as a preferred diagnostic tool. Thus, there exists a substantial need in the art for an ultrasonic imaging probe assembly which permits multiple scan directions without the requirement of manual repositioning of the probe into differing scan positions which are prohibitive due to space constraints in the intended application of use.